Restructure argument passing onto stack

Arguments now are prepended to the execute_data, inside the (last!) temporaries of the previous stack frame. Every stack frame has place for sent arguments plus five optional args (RECV_INIT...) and the execute_data.
This allows EG(vm_stack_top) and EX(call) to be removed and saves us from expensive comparisons to push a call frame completely in some cases (every ICALL).
The only downside is that arguments now are in reverse order causing variadics to be in reverse order on the stack; extensions might need some update ...
Also, freeing of args and execute_data is now completely handled by liveness.
Finally, the patch gives 0.5%-3% improvement on applications.

There likely is still some room for optimization (e.g. eliminating ZEND_SEND_VAL with TMPs or speeding up the unpacking, removing INIT_FCALL for UCALLs, ...).

Author: bwoebi

Zend/tests/arg_unpack/invalid_type.phpt

@@ -16,19 +16,19 @@ test(1, 2, 3, ...new StdClass, ...3.14, ...[4, 5]);
 
 ?>
 --EXPECTF--
-Warning: Only arrays and Traversables can be unpacked in %s on line %d
+Warning: Argument unpacking at parameter 1 requires array or Traversable, null given in %s on line %d
 array(0) {
 }
 
-Warning: Only arrays and Traversables can be unpacked in %s on line %d
+Warning: Argument unpacking at parameter 1 requires array or Traversable, integer given in %s on line %d
 array(0) {
 }
 
-Warning: Only arrays and Traversables can be unpacked in %s on line %d
+Warning: Argument unpacking at parameter 1 requires array or Traversable, object of type stdClass given in %s on line %d
 array(0) {
 }
 
-Warning: Only arrays and Traversables can be unpacked in %s on line %d
+Warning: Argument unpacking at parameter 4 requires array or Traversable, string given in %s on line %d
 array(5) {
   [0]=>
   int(1)
@@ -42,9 +42,9 @@ array(5) {
   int(5)
 }
 
-Warning: Only arrays and Traversables can be unpacked in %s on line %d
+Warning: Argument unpacking at parameter 4 requires array or Traversable, object of type stdClass given in %s on line %d
 
-Warning: Only arrays and Traversables can be unpacked in %s on line %d
+Warning: Argument unpacking at parameter 4 requires array or Traversable, float given in %s on line %d
 array(5) {
   [0]=>
   int(1)

Zend/zend_API.c

@@ -70,7 +70,7 @@ ZEND_API int zend_get_parameters(int ht, int param_count, ...) /* {{{ */
 			ZVAL_COPY_VALUE(param_ptr, &new_tmp);
 		}
 		*param = param_ptr;
-		param_ptr++;
+		param_ptr--;
 	}
 	va_end(ptr);
 
@@ -97,7 +97,7 @@ ZEND_API int zend_get_parameters_ex(int param_count, ...) /* {{{ */
 	while (param_count-->0) {
 		param = va_arg(ptr, zval **);
 		*param = param_ptr;
-		param_ptr++;
+		param_ptr--;
 	}
 	va_end(ptr);
 
@@ -120,7 +120,7 @@ ZEND_API int _zend_get_parameters_array_ex(int param_count, zval *argument_array
 	while (param_count-->0) {
 		ZVAL_COPY_VALUE(argument_array, param_ptr);
 		argument_array++;
-		param_ptr++;
+		param_ptr--;
 	}
 
 	return SUCCESS;
@@ -144,7 +144,7 @@ ZEND_API int zend_copy_parameters_array(int param_count, zval *argument_array) /
 			Z_ADDREF_P(param_ptr);
 		}
 		zend_hash_next_index_insert_new(Z_ARRVAL_P(argument_array), param_ptr);
-		param_ptr++;
+		param_ptr--;
 	}
 
 	return SUCCESS;
@@ -2158,6 +2158,7 @@ ZEND_API int zend_register_functions(zend_class_entry *scope, const zend_functio
 		internal_function->function_name = zend_new_interned_string(zend_string_init(ptr->fname, fname_len, 1));
 		internal_function->scope = scope;
 		internal_function->prototype = NULL;
+		internal_function->stack_size = ZEND_CALL_FRAME_SLOT * ZEND_MM_ALIGNED_SIZE(sizeof(zval));
 		if (ptr->flags) {
 			if (!(ptr->flags & ZEND_ACC_PPP_MASK)) {
 				if (ptr->flags != ZEND_ACC_DEPRECATED || scope) {

Zend/zend_API.h

@@ -767,7 +767,7 @@ ZEND_API ZEND_COLD void ZEND_FASTCALL zend_wrong_callback_error(int severity, in
 	if (_optional) { \
 		if (UNEXPECTED(_i >_num_args)) break; \
 	} \
-	_real_arg++; \
+	_real_arg--; \
 	_arg = _real_arg; \
 	ZVAL_DEREF(_arg); \
 	if (separate) { \
@@ -1004,7 +1004,7 @@ ZEND_API ZEND_COLD void ZEND_FASTCALL zend_wrong_callback_error(int severity, in
 			ZEND_ASSERT(_i <= _min_num_args || _optional==1); \
 			ZEND_ASSERT(_i >  _min_num_args || _optional==0); \
 			if (_optional && UNEXPECTED(_i >_num_args)) break; \
-			_real_arg++; \
+			_real_arg--; \
 			zend_parse_arg_zval(_real_arg, &dest, check_null); \
 		}
 
@@ -1023,10 +1023,10 @@ ZEND_API ZEND_COLD void ZEND_FASTCALL zend_wrong_callback_error(int severity, in
 #define Z_PARAM_VARIADIC_EX(spec, dest, dest_num, post_varargs) do { \
 		int _num_varargs = _num_args - _i - (post_varargs); \
 		if (EXPECTED(_num_varargs > 0)) { \
-			dest = _real_arg + 1; \
+			dest = _real_arg - 1; \
 			dest_num = _num_varargs; \
 			_i += _num_varargs; \
-			_real_arg += _num_varargs; \
+			_real_arg -= _num_varargs; \
 		} else { \
 			dest = NULL; \
 			dest_num = 0; \

Zend/zend_builtin_functions.c

@@ -438,10 +438,9 @@ ZEND_FUNCTION(func_num_args)
    Get the $arg_num'th argument that was passed to the function */
 ZEND_FUNCTION(func_get_arg)
 {
-	uint32_t arg_count, first_extra_arg;
 	zval *arg;
 	zend_long requested_offset;
-	zend_execute_data *ex;
+	zend_execute_data *ex = EX(prev_execute_data);
 
 	if (zend_parse_parameters(ZEND_NUM_ARGS(), "l", &requested_offset) == FAILURE) {
 		return;
@@ -458,19 +457,12 @@ ZEND_FUNCTION(func_get_arg)
 		RETURN_FALSE;
 	}
 
-	arg_count = ZEND_CALL_NUM_ARGS(ex);
-
-	if (requested_offset >= arg_count) {
+	if (requested_offset >= ZEND_CALL_NUM_ARGS(ex)) {
 		zend_error(E_WARNING, "func_get_arg():  Argument " ZEND_LONG_FMT " not passed to function", requested_offset);
 		RETURN_FALSE;
 	}
 
-	first_extra_arg = ex->func->op_array.num_args;
-	if (requested_offset >= first_extra_arg && (ZEND_CALL_NUM_ARGS(ex) > first_extra_arg)) {
-		arg = ZEND_CALL_VAR_NUM(ex, ex->func->op_array.last_var + ex->func->op_array.T) + (requested_offset - first_extra_arg);
-	} else {
-		arg = ZEND_CALL_ARG(ex, requested_offset + 1);
-	}
+	arg = ZEND_CALL_ARG(ex, requested_offset + 1);
 	if (EXPECTED(!Z_ISUNDEF_P(arg))) {
 		ZVAL_DEREF(arg);
 		ZVAL_COPY(return_value, arg);
@@ -483,8 +475,7 @@ ZEND_FUNCTION(func_get_arg)
 ZEND_FUNCTION(func_get_args)
 {
 	zval *p, *q;
-	uint32_t arg_count, first_extra_arg;
-	uint32_t i, n;
+	uint32_t arg_count, i, n;
 	zend_execute_data *ex = EX(prev_execute_data);
 
 	if (ZEND_CALL_INFO(ex) & ZEND_CALL_CODE) {
@@ -496,29 +487,12 @@ ZEND_FUNCTION(func_get_args)
 
 	array_init_size(return_value, arg_count);
 	if (arg_count) {
-		first_extra_arg = ex->func->op_array.num_args;
 		zend_hash_real_init(Z_ARRVAL_P(return_value), 1);
 		ZEND_HASH_FILL_PACKED(Z_ARRVAL_P(return_value)) {
 			i = 0;
 			n = 0;
 			p = ZEND_CALL_ARG(ex, 1);
-			if (arg_count > first_extra_arg) {
-				while (i < first_extra_arg) {
-					q = p;
-					if (EXPECTED(Z_TYPE_INFO_P(q) != IS_UNDEF)) {
-						ZVAL_DEREF(q);
-						if (Z_OPT_REFCOUNTED_P(q)) { 
-							Z_ADDREF_P(q);
-						}
-						n++;
-					}
-					ZEND_HASH_FILL_ADD(q);
-					p++;
-					i++;
-				}
-				p = ZEND_CALL_VAR_NUM(ex, ex->func->op_array.last_var + ex->func->op_array.T);
-			}
-			while (i < arg_count) {
+			do {
 				q = p;
 				if (EXPECTED(Z_TYPE_INFO_P(q) != IS_UNDEF)) {
 					ZVAL_DEREF(q);
@@ -528,9 +502,9 @@ ZEND_FUNCTION(func_get_args)
 					n++;
 				}
 				ZEND_HASH_FILL_ADD(q);
-				p++;
+				p--;
 				i++;
-			}
+			} while (i < arg_count);
 		} ZEND_HASH_FILL_END();
 		Z_ARRVAL_P(return_value)->nNumOfElements = n;
 	}
@@ -2243,25 +2217,6 @@ static void debug_backtrace_get_args(zend_execute_data *call, zval *arg_array) /
 
 		zend_hash_real_init(Z_ARRVAL_P(arg_array), 1);
 		ZEND_HASH_FILL_PACKED(Z_ARRVAL_P(arg_array)) {
-			if (call->func->type == ZEND_USER_FUNCTION) {
-				uint32_t first_extra_arg = call->func->op_array.num_args;
-
-				if (ZEND_CALL_NUM_ARGS(call) > first_extra_arg) {
-					while (i < first_extra_arg) {
-						if (EXPECTED(Z_TYPE_INFO_P(p) != IS_UNDEF)) {
-							if (Z_OPT_REFCOUNTED_P(p)) {
-								Z_ADDREF_P(p);
-							}
-							n++;
-						}
-						ZEND_HASH_FILL_ADD(p);
-						p++;
-						i++;
-					}
-					p = ZEND_CALL_VAR_NUM(call, call->func->op_array.last_var + call->func->op_array.T);
-				}
-			}
-
 			while (i < num_args) {
 				if (EXPECTED(Z_TYPE_INFO_P(p) != IS_UNDEF)) {
 					if (Z_OPT_REFCOUNTED_P(p)) {
@@ -2270,7 +2225,7 @@ static void debug_backtrace_get_args(zend_execute_data *call, zval *arg_array) /
 					n++;
 				}
 				ZEND_HASH_FILL_ADD(p);
-				p++;
+				p--;
 				i++;
 			}
 		} ZEND_HASH_FILL_END();

Zend/zend_closures.c

@@ -147,7 +147,7 @@ ZEND_METHOD(Closure, call)
 
 	fci.retval = &closure_result;
 	fci.params = my_params;
-	fci.param_count = my_param_count;
+	fci.param_count = -my_param_count;
 	fci.object = fci_cache.object = newobj;
 	fci_cache.initialized = 1;
 	fci_cache.called_scope = Z_OBJCE_P(newthis);